Zen X-Fi3 into Denon mini system

Rocker

I often connect my little Zen personal player to our Denon mini system in the kitchen.  I use the headphone out on the Zen into the Portable in on the Denon.

It works fairly well but the Denon has to be turned up very far before music pours forth.  Normal radio on the Denon is at 20 on the volume scale, it is between 45 and 50 for the Zen for equivalent volume.

AFAIK there is no setting on the Denon to increase the sensitivity of the Portable in socket.  Any suggestions on how to get louder music for the same volume setting as Radio.  The little Denon seems to run out of steam at volume settings over 45 [compared to a CD that is]

Thanks.

TTony

Plug it in via a headphone amp?